SummaryThe most influential Shi'ite cleric in Iraq called on the country's leaders on Friday to choose a prime minister within the next four days, a dramatic political intervention that could hasten the end of Nuri al-Maliki's eight year rule.

The most influential Shi'ite cleric in Iraq called on the country's leaders on Friday to choose a prime minister within the next four days, a dramatic political intervention that could hasten the end of Nuri al-Maliki's eight year rule.

Grand Ayatollah Ali Sistani, who commands unswerving loyalty from many Shi'ites in Iraq and beyond, said political blocs should agree on the next premier, parliament speaker and president before a newly-elected legislature meets on Tuesday.

Sistani's intervention makes it difficult for Maliki to stay on as caretaker leader as he has since a parliamentary election in April. That means he must either build a coalition to confirm himself in power for a third term or step aside.

Sistani's message was delivered after a meeting of Shi'ite factions including Maliki's State of Law coalition failed to agree a consensus candidate for prime minister.

The United States and other countries are pushing for a new, inclusive government to be formed as quickly as possible to counter the insurgency led by an offshoot of al Qaeda, the Islamic State in Iraq and the Levant.

The embattled Maliki accused his political foes of trying to prevent parliament from meeting on time and stirring up violence to interfere with the political process.

"They worked to postpone the elections... and now they are working to postpone the first session of the council of representatives... but if they are not able to pressure us to postpone, they will go for inciting security incidents in Baghdad," he said during a televised meeting with commanders.

Over the past fortnight, militants have overrun most majority Sunni areas in north and western Iraq with little resistance, advancing to within an hour's drive of Baghdad.

Iraq's million-strong army, trained and equipped by the United States at a cost of some $25 billion, largely evaporated in the north after the militants launched their assault with the capture of the city Mosul on June 10.

Thousands of Shi'ite volunteers have responded to an earlier call by Sistani for all Iraqis to rally behind the military to defeat the insurgents.

Under Iraq's governing system put in place after the fall of Saddam Hussein, the prime minister has always been a Shi'ite, the largely ceremonial president a Kurd and the speaker of parliament a Sunni. Negotiations over the positions have often been drawn out: after the last election in 2010 it took nearly 10 months for Maliki to build a coalition to stay in office.